Use of a textile material as a safety barrier to protect users of any type of construction on the occurrence of damage to structural and non-structural elements

ABSTRACT

The present invention relates to the use of a textile material as a safety barrier for reducing harm to people in the event of failure of structural and non-structural elements of any type of construction. In particular, the present invention relates to a method for containing a non-structural clay building element which may be deformed following breakage of the same due to a collapse. Finally, the present invention relates to a method for imparting safety to people who are inside an environment confined by the presence of at least one non-structural element. According to the invention, a layer of fabric comprising a weft and a warp is applied on said structural or non-structural element.

The present invention relates to the use of a textile material as asafety barrier for reducing harm to people in the event of damage tostructural and non-structural elements of any type of construction. Inparticular, the present invention relates to a method for containing anon-structural clay building element following the breakage thereof.Finally, the present invention relates to a method for imparting safetyto people who are inside an environment confined by the presence of atleast one non-structural element.

The civil engineering sector is the branch of engineering dedicated tothe design of constructions and infrastructures intended for civil useand, therefore, all related fields: environmental, building,geotechnical, infrastructural, hydraulic and structural engineering, andurban and land use planning.

The above-mentioned constructions consist of a “load-bearing structure”(structural part) and all accessory “non-load-bearing” parts(non-structural parts).

The resistant structure (or load-bearing structure or more simplystructure) of a construction (e.g. a residential dwelling, bridges andviaducts, industrial buildings) is the part of the construction itselfwhich is expressly intended to absorb the loads and external forces theconstruction is subject to during its working lifetime.

The expression “non-structural part” means all those elements which,though they belong to a construction, do not have the task of absorbingworking loads, e.g. flooring, screeds, insulation, false-ceilings,masonry panels, masonry walls, partitions (walls dividing interiorspaces), curtain walls (walls that “close off” the building, separatingthe interior space from the outside, of varying thickness), decoration,parapets, plaster and installations.

During the lifetime of a construction, both the “structural” and“non-structural” parts can undergo damage, which may be ascribable bothto the normal use thereof and resulting wear and to exceptional eventssuch as, for example, bursts, explosions, impacts or earthquakes.

Moreover, during the lifetime of a construction, it may happen that thelatter needs to undergo modifications of a structural and non-structuralnature or is called upon to withstand greater loads than those for whichit was originally designed, and that failures manifest themselves overtime as a result, for example, of an incorrect initial design.

Following any of the above-described events, the load-bearing structureof the construction, consisting of structural elements, will have to berestored and/or reinforced in order to prevent the collapse of theconstruction itself.

A known method for strengthening and structurally reinforcing aconstruction is to apply fibre-reinforced materials with a continuousfibre polymer matrix (also known as fibre-reinforced composites or FRP)on the structural elements.

The expression “structural strengthening” is used to indicate allbuilding interventions aimed at restoring or preventively increasing thestrength of existing construction work.

FRP fibre-reinforced composites (in short FRP composites) are compositematerials consisting of reinforcement fibres embedded in a polymermatrix. These composites are available in different geometries, such aspultruded sheets, used for example to reinforce elements having regularsurfaces. In FRP fibre-reinforced composites the fibres play a role asload-bearing elements both in terms of strength and stiffness, whereasthe matrix, in addition to protecting the fibres, acts as an element fortransferring stresses among the fibres and, if necessary, between thelatter and the structural element the composite has been applied to. Themajority of FRP composites consist of fibres which possess high strengthand stiffness, whereas the strain at break thereof is lower than that ofthe matrix.

It is important to distinguish the matrices, used in the impregnation ofthe fibres, from the adhesives, which are instead used for theapplication of pultruded laminates to the surfaces to be reinforced.

One of the main functions of a matrix in a composite is to “holdtogether” the fibres (reinforcement), thereby assuring cohesion betweenthe fibres of a same layer and between adjacent layers.

Adhesives, on the other hand, perform the function of connecting theelement to be reinforced to the composite and transferring forcesbetween them.

The matrices most widely used to manufacture FRP fibre-reinforcedcomposites are polymers based on thermosetting resins. The mostwidespread thermosetting resins are epoxies. Polyester or vinyl esterresins are also employed.

The fibres most widely used for the production of composites forstructural reinforcement are glass, carbon and aramid fibres.

The use of FRP fibre-reinforced composites for the structuralreinforcement of reinforced concrete (RC for short), prestressedreinforced concrete (PRC for short) and masonry structures is wellknown.

The load-bearing structure of RC and PRC buildings consists of columns,beams, walls, stairways and floors and is thus the part of aconstruction that carries the weight of all the elements making up thebuilding, supporting and supported (e.g. walls, floors, furniture,etc.), and transfers it onto the foundations.

A mechanical system composed of beams connected to each other and to theground (through columns) is called a “frame”. This system represents oneof the most important structural arrangements used in construction.Walls are structural elements for supporting other elements (in a manneranalogous to columns).

Floors are constructive elements which horizontally divide the spaces ofa building; they are flat two-dimensional structures loadedperpendicular to their plane, with a prevalent unidirectional strengthbehaviour (bending strength under vertical load).

In buildings with a masonry load-bearing structure, the walls serve totransfer the weight of the overlying structures to the ground. Based onthe entity of the load it must support, the wall must be more or lessthick.

The masonry can be made, for example, with solid or perforated clayblocks, concrete blocks or natural stone blocks. Said elements aregenerally assembled by means of mortar, which achieves the adhesion.

FRP composites for external structural reinforcement or strengthening ofstructures can be classified into two categories.

The first relates to pre-formed systems which are prepared in thefactory by pultrusion or lamination. The pre-formed composites can beused both for external reinforcement, glued to the structural element tobe reinforced, or as internal reinforcement elements (bars forreinforced concrete structures) totally or partially replacingtraditional steel reinforcements or surface reinforcing bars (e.g. barsinstalled in proximity to the surface).

The second relates to systems impregnated on site, which consist ofsheets of fibres that are impregnated with a resin.

However, the systems impregnated on site pose a drawback given by thefact that it is not possible to estimate a priori, with sufficientaccuracy, the final thickness of the laminate, and it is thus advisableto use pre-formed systems.

Therefore, the use of systems impregnated on site is strongly limited bythe above-mentioned applicative limits.

Strengthening by means of FRP is achieved by “gluing” the compositematerial to the structural element that needs to be reinforced. Thestrengthening operation consists in compensating for the inadequatestrength of a structural element by means of the composite material,which, based on its physical-mechanical characteristics and the methodof application, is capable of developing a certain degree of strength.

The gluing, achieved using adhesives, must be carried out in such a waythat forces can be correctly transferred between the element to bereinforced and the composite.

Correct adhesion of the composite to the substrate is of fundamentalimportance to ensure that the reinforcement is efficacious.

Experimental tests have shown that one of the collapse modes mostfrequently observed in reinforced elements such as RC beams or masonrypanels, with sheets or layers of FRP composites, consists in a prematurefailure at the adhesive interface due to a loss of adherence, usuallyindicated with the term “debonding”. Debonding can manifest itselfwithin the adhesive, between the concrete and adhesive, in the concreteor within the reinforcement composite. Therefore, debonding represents amajor limit to the use of these composite materials.

Experimental results have demonstrated that debonding occurs within theweaker adherent, generally represented by the material making up theelement to be reinforced, with consequent detachment of a more or lessthick layer of RC or masonry in contact with the resin which joins thesheets on one side and the existing substrate on the other. Oncedebonding occurs, the reinforcement will cease taking up any loadbecause of the detachment.

Therefore, debonding represents a major limit to the use of thesecomposite materials.

Another limit posed by composite materials is given by durability. Theterm durability means the capacity of the composite material to maintainthe mechanical characteristics of interest constant over time.

The main problems which involve durability are environmental actions andload transfer modes. Environmental actions have an impact both on theresins and fibres of the various FRP composites, which will degrade,thus exhibiting impaired mechanical properties after exposure to certainenvironmental factors, such as temperature, humidity, UV rays, chemicalagents, etc. The mechanical properties of some FRP composites may alsodegrade as a result of fatigue, which is a mechanical phenomenon wherebya material subjected to variable loads over time (in a regular manner orunder random “cyclic loading”) is damaged until breaking, even thoughthe maximum intensity of the loads in question is significantly lowerthan the ultimate load of the material itself under static conditions.

In the case of the construction of a non-structural element such as awall (or a masonry panel), the latter is in practice constructed byassembling bricks with mortar; these are arranged starting from a firstsurface or lower floor until arriving at a second surface or upperfloor. However, in proximity to said second surface or upper floor thewall is not anchored or fixed to the upper floor. The same applies forthe outer parts of the wall (shoulders), which are not in practiceanchored or fixed to other existing walls or surrounding columns.

Therefore, should a catastrophic event occur, said walls risk collapsingwith extreme ease, causing damage to property and injury to people whoare in the vicinity of said walls.

It thus becomes necessary to have a method for securely anchoring aconstruction comprising one or more non-structural elements, such asmasonry walls, partitions or panels to the surrounding structures andmaking it safer without modifying the normal installation thereof,without adding weight to the non-structural element and withoutimparting stiffness and strength to the construction.

It may also happen that non-structural elements such as curtain wallsand partitions undergo breakage despite remaining connected to theload-bearing structures.

In particular, it becomes necessary to have a material which, onceapplied in contact with a non-structural clay building element, such as,for example, a curtain wall or a partition, is capable of containing theclay parts that could form following the collapse of the non-structuralelement itself in the event of breakage. By virtue of their “continuous”nature, FRP fibre-reinforced composite materials prevent the elements tobe reinforced they are applied to from breathing.

This lack of breathability represents a major limit to the applicationof FRP composites, especially in residential buildings. Therefore, it isinadvisable to apply a composite material on a masonry panel having alarge surface area.

It is thus necessary to have a material and a method for applying thesame which is capable of overcoming the limits and drawbacks of thecomposites present on the market.

Moreover, it becomes necessary to have a material which, once applied incontact with a non-structural element, is capable of imparting greatersafety to the environment where said non-structural element is presentso as to assure greater safety for the people who are inside saidenvironment.

For example, in the event of pieces breaking away from the bottom of afloor or other ceiling failures, it would be useful to be able tocontain and hold back the debris, which would otherwise fall into theroom below and could cause physical harm to the occupants.

A subject matter of the present invention relates to a method forcontaining a non-structural element having the characteristics as setforth in the appended independent claim.

Another subject matter of the present invention relates to a method forimparting safety to people in a room having the characteristics as setforth in the appended independent claim.

Another subject matter of the present invention relates to the use of atextile material as a safety barrier having the characteristics as setforth in the appended independent claim.

Other preferred embodiments of the present invention will be illustratedbelow in the present description without limiting the scope of theinvention in any way. Table 1 shows the data related to the tests fordetermining the bending tensile strength.

FIG. 1 shows a graph related to the determination of bending tensilestrength performed on a hollow flat block without any reinforcement ortextile material (block S) according to the present invention.

FIG. 2 shows a graph related to the determination of bending tensilestrength performed on a hollow flat block having a layer of textilematerial (block 1B-1) according to the present invention on one outsideface (lower face).

FIG. 3 shows a graph related to the determination of bending tensilestrength performed on a hollow flat block having a layer of textilematerial (block 2B) according to the present invention on two outsidefaces.

FIG. 4 shows a photograph related to the determination of bendingtensile strength performed on a hollow flat block (see graph in FIG. 1).

FIG. 5 shows a photograph related to the determination of bendingtensile strength performed on a hollow flat block (see graph in FIG. 2).

FIG. 6 shows a photograph related to the determination of bendingtensile strength performed on a hollow flat block having a layer offabric according to the present invention on the two outside faces (seegraph in FIG. 3).

After lengthy research and experimentation, the Applicant selected acategory of textile materials capable of providing a suitable answer tothe above-mentioned drawbacks.

In the context of the present invention, “textile material” means afabric having a weft and a warp, as described hereunder.

In the context of the present invention, “fabric” or “textile material”is not meant to include a composite material, such as, for example, anFRP composite.

The textile material or fabric of the present invention is characterisedin that it has an “elastic” strength that favours a “ductile” break of anon-structural element, in contrast with FRP composites, which favour a“brittle” break. A brittle break is what occurs with a sudden failure,in an unexpected manner, without leaving the occupants any possibilityof finding shelter. The material of our invention, in contrast, is basedon an “elastic” strength that favours a “ductile”, more progressivebreak that allows time for anyone who is inside the construction at thetime the breakage occurs to react and escape if necessary. This is therevolutionary and innovative concept of this invention.

The textile materials or fabrics of the present invention havecharacteristics of elasticity that may vary from 5 to 40% of elongationaccording to standard UNI EN ISO 13934-1:2000. Preferably, theelasticity may vary within a range comprised from 8 to 35% ofelongation; even more preferably within a range comprised from 10 to 30%of elongation.

In a preferred embodiment, the fabrics of the present invention havecharacteristics of elasticity that may vary from 12 to 25% of elongationaccording to standard UNI EN ISO 13934-1:2000.

In another preferred embodiment, the fabrics of the present inventionhave characteristics of elasticity that may vary from 15 to 20% ofelongation according to standard UNI EN ISO 13934-1:2000.

The textile material is a fabric which comprises at least a weft and atleast a warp. The fabric is obtained by weaving weft yarns and warpyarns.

Preferably, the weft comprises or, alternatively, consists of at leastone high-strength fibre yarn. In a preferred embodiment, said fibre isselected from the group comprising polyester fibres, polyethylenefibres, aramid, polypropylene and polyolefin fibres and the like. Inanother preferred embodiment, said fibre is selected from the groupconsisting of polyester fibres, polyethylene fibres, aramid,polypropylene and polyolefin fibres and the like.

Preferably, the warp comprises or, alternatively, consists of at leastone high-strength fibre yarn. In a preferred embodiment, said fibre isselected from the group comprising polyester fibres, polyethylenefibres, aramid, polypropylene and polyolefin fibres and the like. Inanother preferred embodiment, said fibre is selected from the groupconsisting of polyester fibres, polyethylene fibres, aramid,polypropylene and polyolefin fibres and the like.

In a preferred embodiment, said weft and/or said warp can furthercomprise at least one metal thread selected from the group comprisingsteel and copper threads and the like having a diameter comprised from0.05 mm to 1 mm. Preferably, the diameter is comprised from 0.10 to 0.80mm.

In another preferred embodiment, said weft and/or said warp can furthercomprise at least one metal thread selected from the group comprisingsteel and copper threads and the like having a diameter comprised from0.15 mm to 0.60 mm. Preferably, the diameter is comprised from 0.20 to0.50 mm.

In a preferred embodiment, the weft and/or warp comprise a metal threadof steel having a diameter comprised from 0.10 mm to 0.50 mm; preferably0.20 mm.

In a preferred embodiment, the weft and/or warp comprise a metal threadof copper having a diameter comprised from 0.10 mm to 0.50 mm;preferably 0.20 mm.

The high-strength fibre yarns can be used both in a single ply of onlyone of the high-strength fibres selected from the group comprisingpolyester fibres, polyethylene fibres, aramid, polypropylene andpolyolefin fibres and the like, such as steel, copper and the like, andin a yarn composed of a number of yarn elements of the above fibres(twisted yarn), possibly reinforced with filaments of a metallic nature.The count of singly ply yarns or those resulting from the twisting of anumber of elements have a final count greater than 500 deniers. Thereexists no upper limit, since yarns that are extremely thick, but have adensity proportioned to the overall weight of the fabric, could beadvantageously used without modifying the final result. It is in factwell known in the art that the tensile strength of a fabric depends onthe total number of centinewtons/dtx for a flat section of fabric,generally stated over 5 cm.

In a preferred embodiment, the textile material of the present inventioncan be a simple weft and warp fabric, with plain weave, simple twill andother simple textile structures.

In a preferred embodiment, the weft can be made with one or more yarnsof high-strength fibres of the same or different types, possibly twistedtogether, as stated previously for the warp.

This type of orthogonal fabric is produced by means of a manufacturingprocess known to persons skilled in the art using textile machines ofthe loom type commonly present in the sector.

The textile materials of the present invention have a weight comprisedfrom 200 g/m² to 3000 g/m² when they are produced with a weft and warpof high-strength fibres. For example, a fabric made with 4 warp threadsper centimetre, with a resulting count of 6600 den, has a weight of 640g/m², and 4.5 weft threads per centimetre, with a resulting count of6600 den.

The embodiments that envisage the use of one or more metal threads inthe weft and/or warp have a weight comprised from 250 g/m² to 3500 g/m².For example, a fabric called “948 PL HT IRON STRONG” produced with 6warp threads per centimetre of twisted yarn composed of HT polyester anda metallic filament of steel with a diameter of 0.20 mm, and a weft ofthe same thread with 4.5 weft insertions per centimetre, has a weight of950 g/m². Woven with a plain weave structure, the fabric thus composed,evaluated according to standard UNI EN ISO 113934-1:2000, has an averagemaximum warp strength of 5864 N over 50 mm of fabric, with an averageelongation of 26% and a strength per linear metre of 117.30 KN/mt lin.In the weft it has an average maximum strength of 5494 N over 50 mm, anelongation of 24% and a strength per linear metre of 110 KN/Ml.

According to another embodiment of a fabric, called “948 KE IRONSTRONG”, produced with 4 warp threads per centimetre of twisted yarncomposed of two 3300 den aramid yarns and a metallic filament of steelwith a diameter of 0.20 mm twisted together, and a weft with 4.5insertions per centimetre of the same thread, it has a weight of 950g/m². Woven with a plain weave structure, the fabric thus composed,evaluated according to standard UNI EN ISO 113934-1:2000, has an averagemaximum warp strength of 7950 N over 50 mm of fabric, with an averageelongation of 11.8% and a strength per linear metre of 159 KN/mt lin.

In the weft it has an average maximum strength of 6850 N over 50 mm, anelongation of 10.5% and a strength per linear metre of 137 KN/Ml.

The textile material in fabric form of the present invention has validapplication in constructions and residential buildings.

A mechanical system composed of beams connected to each other andconnected to the ground (through columns) is called a “frame”. Thissystem represents one of the most important structural arrangements usedin constructions and residential buildings.

Walls are constructive elements that vertically divide the spaces of abuilding, whereas floors are constructive elements that horizontallydivide the spaces of a building.

The walls can be structural elements for supporting other elements (in amanner analogous to columns) or, alternatively, they can benon-structural elements. Examples of non-structural elements arepartitions, walls or panels of masonry made with perforated bricks andcurtain walls.

Floors are flat two-dimensional structures loaded perpendicular to theirplane, with a prevalent unidirectional strength behaviour (bendingstrength under vertical load). The floors are anchored to the beamsand/or to the walls. The load-bearing structure of the floor can be madeof wood, reinforced concrete or steel with the presence of othermaterials, such as brick elements.

Stairways are constructive elements for vertically connecting twodifferent heights.

In buildings with a masonry load-bearing structure, the walls(structural elements) serve to transfer the weight of the overlyingstructures to the ground. Based on the entity of the load it mustsupport, the wall must be more or less thick. The weight, from the topof the wall, is distributed throughout the thickness thereof, exerting ahomogeneous pressure on the section of the structure.

The masonry can be made, for example, with solid or perforated clayblocks, concrete blocks or natural stone blocks. Said elements aregenerally assembled by means of mortar, which achieves the adhesion.

The material of the present invention is applied on the masonry walls orpanels, be they either structural elements or non-structural elements,on floors and on stairways.

For example, in the case of the construction of a masonry panel (ormasonry wall), the latter is in practice constructed by assemblingbricks with mortar; these are arranged starting from a first surface orlower floor until arriving at a second surface or upper floor.

In a preferred embodiment, once the masonry wall or panel has beenbuilt, the textile material can be anchored thereto by means of a glueor a substance with adhesive properties or by means of mechanical fixingmeans, such as, for example, nails, screws or other fastening means.

Preferably, the textile material can be placed over the entire surfaceof the panel or, alternatively, only on a given portion thereof.

Advantageously, once placed over the surface of the masonry panel orwall, the textile material can also be anchored to said first surface orlower floor and/or to said second surface or upper floor where themasonry wall or panel have been built.

In a preferred embodiment, the textile material is anchored onto theentire lower surface or floor, the entire surface of the masonry panelor wall and the entire upper surface or floor. In practical terms, in anenvironment confined and delimited by a first and a second surfacesituated at a certain distance from each other and connected to eachother by a masonry wall or panel, said surfaces and said masonry panelor wall is completely clad by applying a textile material of the presentinvention on the outside surface thereof.

Alternatively, the textile material is anchored onto a part of the lowersurface or floor, a part of the surface of the masonry panel or wall anda part of the upper surface or floor.

During their working lifetime, masonry walls or panels, be theystructural elements or non-structural elements, can be subject toforces, generated for example by a seismic event, which actperpendicular to the midplane thereof, and by forces which act parallelto said plane.

During a catastrophic event, such as, for example, an earthquake, theforces which act perpendicular to the midplane cause the panels tocollapse by simple overturning, or as a result of vertical bending orhorizontal bending. Whereas the forces parallel to the midplane inducemechanisms of breakage due to combined compressive and bending stressand shear stress in the plane of the panel.

In practical terms, as a result of these forces, the masonry wall orpanel will be divided into smaller parts, which, by falling, causeinjury to people and damage to property.

Thanks to the mechanical properties it possesses, in particular itselastic properties, the textile material of the present invention iscapable of containing (holding together) the parts of the panel whichhave originated from the original intact panel following thecatastrophic event (breakage due to collapse) and preventing said partsfrom causing injury to people or damage to property.

A subject matter of the present invention relates to a method forcontaining a non-structural brick element which can be deformedfollowing breakage of the same due to a collapse, said method comprisingat least a step in which a layer of textile material is applied on saidnon-structural element.

Another subject matter of the present invention relates to a method forimparting safety to people who are in an environment confined by thepresence of at least one non-structural element, said method comprisingat least a step in which a layer of textile material is applied on saidnon-structural element.

Advantageously, the textile material of the present invention can beapplied underneath, or inside, the cladding of the masonry wall and/orpanel. In this manner, the textile material will prevent any brickelements that might originate from perpendicular forces, parallel forcesor in any case forces that can cause breakage, from being expelledoutward, into the adjacent rooms. Consequently, the textile material ofthe present invention is capable of thus protecting the occupantsagainst highly dangerous, and sometimes lethal, events.

Advantageously, when the textile material of the present invention isapplied continuously from the wall to the floor above, the textilematerial binds the wall itself to the floor, preventing “out-of-planeoverturning” of the wall in the event of forces perpendicular thereto.

Advantageously, when the textile material of the present invention isapplied continuously from the floor to the walls below, the textilematerial will ensure that, in the event of sections breaking away fromthe bottom of the floor or other ceiling failures, the debrisoriginating therefrom will be contained and held back and thus not fallinto the environment below, where it could cause physical harm to theoccupants. In this case, the textile material of the present invention,despite not increasing the structural strength of the floor itself (itdoes not support the structure), is capable of containing the debris,enabling people to seek shelter. This fact is confirmed by FIGS. 5 and6, from which it may be seen that at the end of the bending tensilestrength test there is no expulsion of debris from the flat hollow blockbut rather a containment thereof thanks to the elastic properties of thetextile material used.

Unlike FRP composites, the textile material of the present inventionachieves important advantages thanks to its elasticity. In fact, FRPcomposites are used to reinforce the load-bearing structure by adding“strength” to the structure. The composites are hence materialsstiffened with various types of resins and hardened in such a way as tohave mechanical performances similar to those of the various structuralcomponents of the construction, which have fundamentally “rigid”reactions without any substantial elongation. This logic is alsocorrect, because they must react in a manner that is similar to, or inany case homogeneous with, that of the various components of theconstruction in order to be able to adequately add the strength they areintended to give to the construction. If they underwent greaterelongations, the construction would end up breaking apart before thereinforcement has started to transfer its share of strength to thestructural element (construction). If they were stiffer, and lesselastic, the force would first break the reinforcement and then theconstruction, separating the two strengths thereof and making eacheffective only for its own part. That is why it is important for thesestructural reinforcements to exert their peak strength simultaneously(optimal solution) with the peak strength of the part to be reinforced,elongation being equal. For this reason, even when they are used to bindnon-structural elements, they must be stiffened with resins.

In contrast with all that has been stated above, the materials of thepresent invention make elasticity an essential characteristic.

Advantageously, having a weight in grams/square metre comprised from 300to 3500 g/square metre and at the same time highly elastic properties,the textile material can avoid adding weight to the structural elementsand non-structural elements it is applied on while assuring the requiredperformance.

The textile material of the present invention does not increase thestatic strength of the construction comprising the non-structuralelements it is applied on, even though it improves the characteristicsthereof by adequately binding the various elements which form theconstruction. The textile material of the present invention performs anaction that is in a certain sense “complementary” to that of FRPcomposite materials, in that the latter are all aimed at reinforcing thestructural and non-structural parts and better binding them together soas to increase the static strength of the construction. Notwithstandingthis reinforcement and increase in strength, when stresses exceed thecombined strength of the building part and reinforcement, these may inany case collapse and break apart, resulting in a serious hazard to thesafety of occupants.

In contrast, the textile material of the present invention does notbring about any enhancement of the static strength characteristics ofthe structures of the construction (see experimental part), but ratheracts as a barrier for containing any debris that comes detached when thevarious building parts collapse or break as a result of any type ofextraordinary event, be it an earthquake, a structural failure or anexplosion.

Therefore, a subject matter of the present invention relates to the useof a textile material as a safety barrier for reducing harm to people inthe event of failure of structural and non-structural elements of anytype of construction comprising at least one non-structural element.

Moreover, the application of the textile material of the presentinvention is extremely simple, and also cost-effective, since by bindingthe various structural and/or non-structural elements of theconstruction, it makes the entire construction as a whole safer.

As has been amply discussed above, the application of FRP compositematerials requires them to be directly coupled to the constructive partthey have to reinforce, directly upon the latter and without anyinterposed component such as plaster or the like, in order to avoid thephenomenon of debonding.

Therefore, when such reinforcements are applied on existingconstructions, it is necessary to remove the plaster from the walls.Removing plaster and restoring the parts to be reinforced to anunfinished state is sometimes the principal cost.

In contrast, the textile material of the present invention is applied invarious ways, e.g.: i) directly in plaster specially applied on thewall, in the case of new constructions, ii) on top of old, pre-existingplaster already on the wall, or iii) incorporated in new plaster appliedon top of pre-existing plaster, in the case of renovation of a wall.

The non-structural element comprises a midplane and said breakagethrough collapse is caused by a force which acts perpendicular and/orparallel to said midplane of said non-structural element. Said forcesperpendicular to the midplane induce the breakage of the non-structuralelement. Said forces parallel to the midplane induce the breakage of thenon-structural element. The fabric of the present invention is capableof reducing/containing the damage caused by non-structural elements.

The fabric of the present invention differs from composite materials,such as, for example, FRP composites made with glass fibre or carbonfibre, because it is endowed with high ductility deriving from thefabric's characteristics of elasticity. Thus the fabrics of the presentinvention are capable of withstanding large shifts of non-structuralelements without breaking because they are elastic fabrics, unlike thecomposite materials, which are rigid materials and, therefore, onceapplied to the non-structural elements they break.

Advantageously, the fabric of the present invention can be applieddirectly on the non-structural element without the use of a glue orfixing means, simply by applying the fabric together with the plaster.

Experimental Part

The Applicant tested several textile materials, such as the onesspecified below.

Fabric 1: called “948 PL HT IRON STRONG”, having the characteristicsdescribed above.

Fabric 2: called “948 KE IRON STRONG”, having the characteristicsdescribed above.

Tests were carried out on 6 hollow clay blocks with and without thetextile material of the present invention.

Specifically, the bending tensile strength was determined for 6 hollowclay blocks (test 1—Table 1) having the following characteristics:

-   -   No. 1 25×100×6 cm block with a 1.5 cm layer of gauged mortar on        one face (25×100 cm), identified as “S”.    -   No. 2 25×100×6 cm blocks with a 1.5 cm layer of gauged mortar,        coupled with fabric x, on one face (25×100 cm), identified as        “1B-1” and “1B-2”.    -   No. 1 25×100×6 cm block with a 1.5 cm layer of gauged mortar,        coupled with fabric x, on two faces (25×100 cm), identified as        “23”.    -   No. 1 25×100×6 cm block with a 1.5 cm layer of gauged mortar,        coupled with fabric y, on one face (25×100 cm), identified as        “1G”.    -   No. 1 25×100×6 cm block with a 1.5 cm layer of gauged mortar,        coupled with fabric y, on two faces (25×100 cm), identified as        “2G”.        The bending tensile strength was determined for the 6 blocks        (test 1) using a Galdabini/Metrocom universal test machine mod.        PM60 with a 10 kN load cell and following the reference standard        UNI EN 772-6, which provides for a static scheme with a beam        simply rested on supports spaced apart 80 cm and load        concentrated at the midpoint. The results are shown in Table 1.

TABLE 1 Determination of bending tensile strength for 6 hollow clayblocks. Bending tensile Block Test conditions strength S No fabric 3059N 1B-1 With a layer of fabric 1 positioned on the lower face 2675 N 1B-2With a layer of fabric 1 positioned on the upper face 4356 N 1G With alayer of fabric 2 positioned on the lower face 3215 N 2B With 2 layersof fabric 1, one positioned on the 3079 N lower face and one on theupper face 2G With 2 layers of fabric 1, one positioned on the 3230 Nlower face and one on the upper face

The experimental graphs (see FIG. 1 and FIG. 3) illustrate the increasein ductility of the hollow clay blocks (block S and block 2B in FIG. 1and FIG. 3) following the application of fabric 1 of the presentinvention.

The test performed is called “bending test” and consists in theapplication of a progressively increasing load distributed over the axiswhich divides the block in half along its shorter side, and simultaneousmeasurement of the lowering of the axis.

A “brittle” fracture manifests itself suddenly in that the materialbreaks without showing any deformations that might suggest an imminentcollapse and is therefore a very dangerous mechanism.

A “ductile” break on the other hand is a “controlled” break, in thatbefore collapsing the material shows deformations which indicate animminent break (e.g. formation of cracks, sagging, rotations, etc.).

For the sake of simplicity reference will be made to the graph shown inFIG. 1 “Block without reinforcement (S)” and the graph shown in FIG. 3“Block with 2 layer reinforcement 2B” (where reinforcement means thepotential application of one or two layers of textile material 1 of thepresent invention).

The graphs are constructed to show the shift in the point of applicationof the load on the block on the horizontal x-axis and the value of saidload on the vertical y-axis.

In the graph shown in FIG. 1, corresponding to the bending test on theblock without fabric 1, it can be observed that sag increases with loadand the test is interrupted on reaching the breaking shift,corresponding to about 1.70 mm under a load of 300 kg.

In the graph shown in FIG. 3, corresponding to the bending test of theblock having fabric 1 on both sides, the point of breakage of the blockin relation to shift and load values is practically the same as observedin the first graph. However, the test continued up to a shift of about120 mm since the block continued to withstand the load of 300 kg,becoming deformed but remaining confined within the fabric 1 placed onthe upper and lower faces. The 120 mm measured could presumably havebeen higher, but the test was stopped at this deformation value becauseof the constructive limits of the test equipment.

As can be seen from the above-mentioned graphs, the textile material ofthe present invention has an “elastic” strength that favours a “ductile”break, which takes a longer period of time (following a progressivepattern) and allows more time for people who are inside the constructionto react and escape.

Advantageously, the textile material of the present invention can bevalidly applied by using a glue or a substance with adhesive propertiesor mechanical fixing means such as, for example, nails, screws or otherfixing means, directly upon the non-structural element, which ispreferably free of plaster or any other type of finish.

Moreover, once applied on the structural element or non-structuralelement, directly on the plaster-free part, the textile material of thepresent invention represents the finish of the element itself, whichdoes not further need to be plastered or finished.

1. A method for containing a non-structural clay building element whichcan be deformed following breakage of the same due to collapse, saidmethod comprising at least a step in which a layer of fabric comprisinga weft and a warp is applied on said non-structural element.
 2. Themethod according to claim 1, wherein said weft and said warp comprise atleast one yarn of high-strength fibres.
 3. The method according to claim2, wherein said high-strength fibres are selected from the groupcomprising polyester fibres, polyethylene fibres, aramid, polypropyleneand polyolefin fibres and the like.
 4. The method according to claim 1,wherein said weft and/or warp can also comprise at least one metalthread selected from the group comprising steel and copper threads andthe like having a diameter comprised from 0.05 mm to 1 mm.
 5. The methodaccording to claim 4, wherein said weft and/or warp comprise a metalthread of steel or copper having a diameter comprised from 0.10 to 0.50mm; preferably 0.20 mm.
 6. The method according to claim 1, wherein saidnon-structural clay building element is selected from the groupcomprising walls, panels, partitions, curtain walls, floors andstairways.
 7. The method according to claim 1, wherein said layer offabric is applied to a non-structural clay building element by using aglue or a substance with adhesive properties or mechanical fixing means,preferably nails, screws or other fixing means, directly upon thenon-structural clay building element, preferably, said non-structuralclay building element is free of plaster.
 8. The method according toclaim 1, wherein said layer of fabric is applied to a non-structuralclay building element by using a glue or a substance with adhesiveproperties or mechanical fixing means, preferably nails, screws or otherfixing means, directly upon the non-structural clay building element,and directly upon the pre-existing plaster on said non-structural claybuilding element.
 9. A method for imparting safety to people who areinside an environment confined by the presence of at least onenon-structural clay building element, said method comprising at leastone step in which a layer of fabric is applied on said non-structuralclay building element.
 10. A use of a textile material in accordancewith claim 1, as a safety barrier for reducing harm to people in theevent of structural and non-structural failures of any type ofconstruction comprising at least one non-structural clay buildingelement.